Drainage systems that are situated in locations where trash and debris are carried along with the water are ubiquitous. In particular, unless prevented storm drains such as are found in gutters and drainage channels receive trash, cuttings, trimmings and other debris constantly throughout the year and are subject to clogging. During clement weather, the flow of water is usually rather slow, and is insufficient to flush the system, especially at catch basins and bends. Instead, despite regular sweeping upstream from the opening, considerable amounts of trash will enter the drain system, while still permitting the slow flow of water.
Serious trouble arises when later storms or other circumstances present water to these systems at high rates of flow while they are congested with the accumulated trash. Clogging of this system can result in upstream flooding, or the washing downstream of the accumulated material to do its mischief downstream. To avoid this situation, throughout the year maintenance crews are sent to clear out trash and debris that has entered the system through the openings. This is a considerable expense, and in the event that a storm strikes before the system is cleared, serious damage can occur despite those earlier efforts.
It is an object of this invention to provide a gate which will exclude trash and debris from the system while still permitting a slow flow of water, but which will open to allow full access for water (and entrained material) when the rate of flow is sufficiently high. When closed, the gate will permit the trash upstream from it to be removed by routine and collection sweeping, so as to remove trash that otherwise would later be driven into the system.